Princess Eugenie turned 29 at the weekend, taking to Instagram to thank her well wishers and writing that her “28th year was the best one yet”. One person who congratulated Eugenie at the weekend was designer Zac Posen, who posted a never before seen image of Eugenie in the wedding reception dress he designed for her. Posen took to Instagram to wish Princess Eugenie a happy birthday, sharing an image of the gown as he knelt on the ground before her to adjust its long train.

In honour of Princess Eugenie's 29th birthday on Sunday, Zac Posen shared a never-before-seen photograph of the royal's second wedding dress. The American designer took to Instagram to post a lovely tribute, in which he described Eugenie as someone with a "heart of gold and sophisticated humour." He wrote: "Every now and then you meet somebody who just knocks your socks off. This last year I got to know a young lady who possessed natural elegance, a heart of gold and sophisticated humour.""My studio and I had the honour (and the best time) collaborating with her on her special gown," he added. "Best of all she is dedicated to using her privilege to help our world and its people with her project @the_anti_slavery_collective. Happy Birthday! @princesseugenie." After walking the aisle in a bespoke Peter Pilotto gown, the blushing bride changed into a stunning pink number by the famous American designer, which featured long sleeves and a caped shoulder.READ: Princess Eugenie's emotional tribute to husband Jack Brooksbank and their special dayOn designing the royal's wedding reception dress, Zac said in an official statement: "It was an incredible honour to create this dress for Her Royal Highness Princess Eugenie on her wedding day." He continued: "Her grace, elegance and strength perfectly embody everything I could hope for in a woman wearing our design."Loading the player...Elsewhere, Princess Eugenie thanked her social media followers for their birthday well-wishers. Reflecting on her 28th year being "the best one yet" after she tied the knot with her long-term partner Jack Brooksbank in October. "My 28th year was the best one yet. Now to being 29...Thank you for all the birthday wishes," she said. Her mother Sarah Ferguson shared a snap of her youngest daughter to celebrate the day, saying: "Happy Birthday my darling girl xxx." Prince Andrew added: "Wishing @princesseugenie a very Happy Birthday!"MORE: Princess Eugenie reunites with her wedding dress in special visit to royal exhibitionMake sure you never miss a ROYAL story! Sign up to our newsletter to get all of our celebrity, royal and lifestyle news delivered directly to your inbox.